Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis The bright and the dark sides of L carnitine supplementation: a systematic review Journal of the International Society of Sports Nutrition Springer Nature Link Effects of L carnitine over supplementation on spermatogenesis and sperm function in healthy NMRI mice ScienceDirect l carnitine: Nutrition, pathology, and health benefits ScienceDirect L Carnitine: Benefits, Uses, Side Effects, and More